KR20090049607A - Acquisition in frequency division multiple access systems - Google Patents

Abstract

The systems and methods of the present invention enable cell acquisition in a wireless communication system in a frequency division multiple access mode of operation. Code sequences transmitted on the primary sync channel (P-SCH) enable detection of indicators of symbol boundaries, cyclic prefix periods, and broadcast channel bandwidths. Sequences transmitted on the secondary synchronization channel (S-SCH) provide radio frame boundary detection, cell identifier and broadcast channel bandwidth indicator. The cell identifier may be transmitted jointly between P-SCH and S-SCH codes. Broadcast channel sequences carry mild prefix timing, system bandwidth and other system information. The relay of cell acquisition information and multi-cell acquisition when a wireless system operates with frequency reuse are presented.

Description

Acquisition in frequency division multiple access systems {ACQUISITION IN FREQUENCY DIVISION MULTIPLE ACCESS SYSTEMS}

This application claims the priority of US Provisional Application No. 60 / 839,954, filed Aug. 23, 2006, entitled "Method and Apparatus for Acquisition in FDMA Systems," which is incorporated herein by reference.

The present invention generally relates to wireless communications, in particular sequences for acquiring cell information using cell acquisition and synchronization channels and broadcast channels.

Wireless communication systems have been widely deployed to provide various types of communication content such as voice, video, data and the like. These systems can support communication with multiple users by sharing the available system resources (eg, bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. However, irrespective of the specificities of many available wireless communication systems, in each of these systems, the terminal or the wireless device may not be capable of cell acquisition or cell search to operate upon switching-on. cell search). Cell synchronization acquisition is a procedure in which the terminal acquires time and frequency synchronization with the network and also obtains additional identifiers for the cell identifier and system information important for operation such as system bandwidth and antenna configuration of the cell transmitter.

In wireless systems such as 3G third generation long term evolution (LTE) or evolution universal terrestrial radio access (E-UTRA), the presence of a cyclic prefix that mitigates intersymbol interference in orthogonal frequency division multiplexing and system bandwidth versatility Advantageous features that improve communication performance, such as (for example, a 3G LTE system may have multiple BWs, 1.25 MHz, 1.6 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz) may be achieved by initial cell acquisition. Cause inherent complexity. Time synchronization, ie detection of symbol boundaries; Detection of 0.5 ms slot boundary; Detection of 1 ms sub-frame boundary; Detection of 5 ms 1/2 radio frame boundaries; Detection of up to 10 ms radio boundaries; And bandwidth to be used during cell acquisition, physical to be used during cell acquisition, in addition to frequency synchronization requiring detection of a 40 ms broadcast channel transmission time interval and obtaining a downlink frequency that can be used as a frequency reference for uplink transmission. There are complex procedures such as determining the information to be carried by these channels during channel and cell acquisition. Much effort has been put into solving each of these problems, but until now no development of cell acquisition protocols has been developed that is fast, reliable and consumes minimal resources. Thus, there is a need for a cell acquisition protocol with the features set out below.

This description provides a simplified summary that provides a basic understanding of some aspects of the presented embodiments. This summary is not an extensive overview, nor does it describe important elements or limit the scope of the embodiments. The purpose of the summary is to present some concepts of the presented embodiments in a simplified form as a prelude to the more detailed description that is presented later.

According to one aspect, an apparatus operating in a wireless communication environment carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of a broadcast channel bandwidth, and orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub A processor configured to receive a code sequence of a primary synchronization channel that facilitates frame boundary detection; And a memory connected to the processor and storing data.

According to one aspect, an apparatus operating in a wireless communication environment carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth, and orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary A processor configured to transmit a code sequence of a primary sync channel to facilitate detection; And a memory connected to the processor and storing data.

According to one aspect, an apparatus operating in a wireless communication environment using orthogonal frequency division multiple access includes a plurality of detection components that simultaneously obtain a plurality of cell information in a plurality of subcarrier intervals; A processor configured to process the plurality of cell information; And a memory connected to the processor and storing data.

According to one aspect, an apparatus operating in a wireless communication environment carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth, and orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary Means for receiving a code sequence of primary sync channel symbols to facilitate detection; And means for receiving one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth.

According to one aspect, a machine-readable medium comprising instructions which, when executed by a machine, cause the machine to perform the following steps, wherein the steps are one of an indicator of a cyclic prefix period, a portion of a cell identification code, a broadcast channel bandwidth; Receiving a code sequence of primary sync channel symbols, carrying at least one and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection; Receiving one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; And receiving a code sequence of broadcast channel symbols, carrying at least one of a cyclic prefix timing and the wireless system bandwidth.

According to one aspect, a machine-readable medium comprising instructions which, when executed by a machine, cause the machine to perform the following steps, wherein the steps are one of an indicator of a cyclic prefix period, part of a cell identification code, a broadcast channel bandwidth; Transmitting a code sequence of primary sync channel symbols at 1.25 MHz, carrying at least one and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection; And transmitting one or more code sequences of secondary sync channel symbols at 1.25 MHz, carrying at least one of a radio frame boundary, part or all of the cell identification code, and an indicator of broadcast channel bandwidth. Medium is provided.

According to one aspect, a method used in a wireless communication system carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of a broadcast channel bandwidth, and orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary Receiving a code sequence of a primary synchronization channel (P-SCH) to facilitate detection; Receiving one or more code sequences of a secondary synchronization channel (S-SCH), carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; Receiving a code sequence of a broadcast channel (BCH), carrying at least one of cyclic prefix timing and the wireless system bandwidth; And processing the P-SCH, the S-SCH, and the BCH code sequences to extract the cell information carried by the code sequences.

According to one aspect, a method used in a wireless communication system carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of a broadcast channel bandwidth, and orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary Transmitting a code sequence of primary sync channel symbols to facilitate detection; Transmitting one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; And transmitting a code sequence of a broadcast channel, carrying at least one of cyclic prefix timing and the wireless system bandwidth.

To the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following detailed description and the annexed drawings set forth certain illustrative aspects and describe various ways in which the principles of the embodiments may be used. Other advantages and novel features will become apparent from the following detailed description when referring to the drawings, and the presented embodiments include all such aspects and their equivalents.

1 is a diagram illustrating a system in which user equipment obtains cell information from a base station.

2 is a block diagram of a MIMO transmitter and receiver.

3 is a block diagram of a MU-MIMO configuration.

4 is a diagram illustrating transmission configurations of P-SCH codes, S-SCH and BCH-codes.

5A and 5B illustrate the synchronization and broadcast channel bandwidth utilization.

6 is a diagram illustrating information carried by a synchronization channel and a broadcast channel.

7A, 7B, and 7C are diagrams showing sequences of cell acquisition.

8A and 8B are diagrams showing relay of cell information.

9A, 9B, and 9C are diagrams illustrating a system in which a terminal simultaneously acquires cells operating with frequency reuse.

FIG. 10 is a block diagram illustrating a structure of a system in which a terminal simultaneously acquires a plurality of cells operated by frequency reuse.

11 is a flowchart illustrating a method of performing cell acquisition.

12 is a flowchart illustrating a method of relaying cell synchronization information.

13A and 13B are flow diagrams illustrating a method of transmitting and receiving cell information, respectively, using frequency reuse.

14 is a diagram illustrating an example system capable of receiving code sequences of primary and secondary sync channel symbols in accordance with one or more aspects.

Various embodiments are now described with reference to the drawings, wherein like numerals refer to like elements. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. However, it will be apparent that such embodiment (s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

In this specification, the term “exemplary” is used herein to mean use as an example, illustration or illustration. Some aspects or designs described herein as "exemplary" are not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, the use of the term "exemplary" is intended to provide concepts in actual form.

Moreover, the term "or" is intended to mean the generic "or" rather than the exclusive "or". That is, unless otherwise specified, the context "X uses A or B" is intended to mean some of the natural number inclusive permutations. That is, if X uses A, X uses B, or X uses both A and B, then "X uses A or B" is satisfied under some of the examples described above. Moreover, throughout this specification, the singular does not exclude “plurality” unless specifically stated otherwise.

As used herein, the terms “component”, “module”, “system” and the like refer to computer-related entities, hardware, firmware, software, a combination of software and hardware, or the execution of software. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, a thread of execution, a program, and / or a computer. For example, both an application running on a computing device and the computing device can be a component. One or more components can reside within a processor and / or thread of execution, and a component can be localized within one computer or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. Components may be connected via a network such as the Internet and other systems via, for example, signals with one or more data packets (e.g., data and / or signals from one component interacting with other components in a local system or distributed system). Data) and communicate via local and / or remote processes.

Also, various embodiments are described in connection with a wireless terminal. A wireless terminal may be referred to as a system, subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user device, or user equipment (UE). A mobile device may be a cellular telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a portable device with wireless connectivity, a computing device, or another device connected to a wireless modem. It may be a processing device. Moreover, various embodiments are described herein in connection with a base station. A base station can be used to communicate with mobile device (s) and can be referred to as an access point, Node B, or any other terminology.

As used herein, the term “processor” may refer to a classical architecture or a quantum computer. Classical architecture includes single-core processors; Single-processors with software multithread execution capability; Multi-core processors; Multi-core processors with software multithread execution capability; Multi-core processors with hardware multithreaded technology; Parallel platforms; Includes (but is not limited to) parallel platforms with distributed shared memory. In addition, a processor may refer to an application specific integrated circuit (ASIC). Quantum computer architecture can be based on qubits, nuclear magnetic resonance platforms, superconducting Josephson functions, etc., implemented with gated or self-assembled quantum dots. Processors may use nanoscale structures such as, but not limited to, quantum-dot based transistors, switches and gates to optimize space usage and enhance performance of user equipment.

In this description, the term “memory” refers to data stores, algorithmic stores, and other information stores, charts, and databases, such as, but not limited to, image stores, digital music, and video stores. It will be appreciated that the memory components presented herein may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. For example, non-volatile memory may include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM), which acts as external cache memory. For example, the RAM includes synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), improved SDRAM (ESDRAM), synclink DRAM (SLDRAM) and direct Rambus RAM (DRRAM). Many forms are available. In addition, the memory components of the methods and / or systems presented herein include, but are not limited to, these and any other type of memory.

In addition, the various aspects or features presented herein may be embodied in a method, apparatus, or article of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" includes a computer program, carrier, or media accessible from any computer readable device. For example, computer-readable media may include magnetic storage devices (eg, hard disks, floppy disks, magnetic strips, etc.), optical discs (eg, compact discs (CDs), digital versatile discs (DVDs), etc.). ), Smart cards, and flash memory devices (eg, EEPROM, cards, sticks, key drives, etc.). In addition, various storage media presented herein include one or more devices and / or other machine-readable media for storing information. The term “machine-readable medium” includes, but is not limited to, a wireless channel and various other media capable of storing, holding, and / or delivering command (s) and / or data.

 Systems and methods for performing cell acquisition based on code sequences transmitted over a primary sync channel (P-SCH), a secondary sync channel (S-SCH), and a broadcast channel (BCH) are presented below. . Detailed descriptions of the information transmitted by the P-SCH, the S-SCH, and the BCH and the sequences through which the information is transmitted are given. Additionally, multi-cell acquisition is presented when the wireless system operates with frequency reuse as well as relay of cell acquisition information.

를 각각 가진 M개의 주파수 서브캐리어들의 세트에 매핑되며, 여기서

는 시스템 대역폭(예컨대, 1.25MHz, 2.5MHz, 5MHz, 10MHz, 15MHz, 20MHz)이다. 서브캐리어들은 전형적으로 직교 톤들(tone)이다. 직렬/병렬(S/P) 컴포넌트(150)는 N-심볼 길이 시퀀스를 n개의 심볼들의 프레임들로 파싱(parse)하며, 이들 n개의 심볼들을 M개의 서브캐리어들로 매핑한다(S/P 컴포넌트(150)가 또한 도 1에 도시된 바와같이 스탠드 얼론 컴포넌트인 것보다 오히려 시퀀스 생성기 컴포넌트(144)에 위치할 수 있다는 것에 유의해야 한다). 이산 역 고속 푸리에 변환(IFFT) 컴포넌트(152)는 심볼들의 시간 표현을 병렬 프레임들로 생성한다(컴포넌트(152)가 또한 프로세서(142)의 집적부일 수 있다는 것에 유의해야 한다). IFFT를 적용할때, 순환 프리픽스(CP:cyclic prefix)가 각각의 전송된 무선 서브-프레임의 시간-영역 심볼들의 시작부분에 추가된다. CP는 심볼간 간섭(ISI) 및 캐리어간 간섭(ICI)을 방지하기 위하여 가드 간격(guard interval)으로서 도입된다. 병렬 대 직렬 변환기(도시안됨)는 시퀀스 생성기 컴포넌트(142)에 의하여 생성된 각각의 시퀀스에 대한 시간-영역 심볼 스트림을 생성하며, 이들 스트림들은 다운링크(160)로 전송된다. P-SCH(162), S-SCH(164) 및 BCH(166)에 대한 코드 시퀀스들이 생성되어 전송될 수 있다.1 shows that user equipment 120 has a primary sync channel (P-SCH) 162, a secondary sync channel (S-SCH) 164, and a broadcast channel (BCH) 166 over the downlink 160. A system 100 is obtained for obtaining cell information from a base station 140 via code sequences transmitted to the system. User equipment 120 may include detection component 122, processor 124, and memory 126. Base station 140 may include sequence generator component 142, processor 144, and memory 146. Sequence generator component 142 generates code sequences that may include cell search information such as system bandwidth, antenna configuration of base station 140 (see below), cell identifier (ID), and the like. The sequences have N symbol lengths and the number of bits in the symbol depends on the modulation constellation used (eg BPSK, QPSK, 16-QAM, 64-QAM). Sequences may be pseudorandom codes (eg, Gold, Walsh-Hadamar, M-sequences (maximum length sequences), and pseudonoise sequences) or generalized chirped sequences (eg, Zadoff-Chu). May be). In Orthogonal Frequency Division Multiple Access (OFDMA), information streams are frequency spaced.

Mapped to a set of M frequency subcarriers each having

Is the system bandwidth (e.g., 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz). Subcarriers are typically orthogonal tones. Serial / parallel (S / P) component 150 parses an N-symbol length sequence into frames of n symbols and maps these n symbols to M subcarriers (S / P component). It should be noted that 150 may also be located in sequence generator component 144 rather than being a standalone component as shown in FIG. 1). Discrete Inverse Fast Fourier Transform (IFFT) component 152 generates the temporal representation of the symbols in parallel frames (note that component 152 may also be an integral part of processor 142). When applying the IFFT, a cyclic prefix (CP) is added to the beginning of the time-domain symbols of each transmitted radio sub-frame. CP is introduced as a guard interval to prevent inter-symbol interference (ISI) and inter-carrier interference (ICI). A parallel-to-serial converter (not shown) generates a time-domain symbol stream for each sequence produced by sequence generator component 142, which is sent to downlink 160. Code sequences for the P-SCH 162, S-SCH 164, and BCH 166 may be generated and transmitted.

Base station 140 may also include artificial intelligence (AI) component 148. The term "intelligence" refers to the ability to make inference decisions about the current or pre-state of a system based on existing information about the system. Artificial intelligence can be used to identify a specific situation or action and generate a probability distribution over a particular state of the system without human intervention. Artificial intelligence is based on a set of data available on the system, such as advanced mathematical algorithms (e.g., decision trees, neural networks, regression analysis, cluster analysis, genetic algorithms, and reinforcement). learning)). In particular, the AI component 148 learns from the data according to the implementation of the various automated aspects presented below, and models constructed by such learning (eg, Hidden Markov Models and associated prototype dependency models). ), More general stochastic graphical models such as Bayesian Networks, linear classifiers such as Support Vector Machines (SVMs), generated by structural search using Bayesian model scores or approximation, "Nonlinear classifiers, such as methods, fuzzy logic methods, methods referred to as other methods of performing data fusion, etc.) may be used.

In user equipment 120, the detection component 122, which may include a correlator 128 and a fast Fourier transform component, may include P-SCH 162 codes, S-SCH 164 codes, and BCH 166 codes. And perform cell acquisition to allow user equipment 120 to communicate with base station 140. Detection and information carried by P-SCH codes, S-SCH codes and BCH codes according to aspects of the present invention are presented in more detail below.

2 illustrates a transmitter system 210 (eg, base station 140) and a receiver of a multiple-input multiple-output (MIMO) system that may provide for sector communication in a wireless communication environment in accordance with one or more aspects presented herein. A block diagram illustrating one embodiment of a system 250 (eg, user equipment 120). In transmitter system 210, traffic data for multiple data streams may be provided from data source 212 to transmit (TX) data processor 214. In one embodiment, each data stream is transmitted via a respective transmit antenna. TX data processor 214 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data. Coded data for each data stream may be multiplexed with pilot data using OFDM techniques. Pilot data is typically a known data pattern that can be processed in a known manner and used in a receiver system to estimate the channel response. Next, the multiplexed pilot and coded data for each data stream is then selected for a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying) selected for the data stream to provide modulation symbols. (QPSK), multiple phase-shift keying (M-PSK) or m-order quadrature amplitude modulation (M-QAM)] (e.g., symbol mapped). The data rate, coding, and modulation for each data stream can be determined by the instructions executed by the processor 230.

Modulation symbols for all data streams are then provided to a TX MIMO processor 220 that can further process the modulation symbols (eg, OFDM). TX MIMO processor 220 then provides N _T modulation symbol streams to N _T transmitters (TMTR) 222a through 222t. In some embodiments, TX MIMO processor 220 applies beamforming weights (or precoding) to the symbols of the data streams and to the antenna from which the symbol is transmitted. Each transmitter 222 receives and processes each symbol stream to provide one or more analog signals, and further conditioned the analog signals to provide a modulated signal suitable for transmission over a MIMO channel (eg, Amplify, filter and upconvert). Then, N _T modulated signals from transmitters (222 to 222 _{A T)} are transmitted from the N _T antennas (224 ₁ to 224 _T), respectively. In receiver system 250, the transmitted modulated signals are received by N _R antennas 252 ₁ through 252 _R , and the received signal from each antenna 252 is received by each receiver (RCVR) 254 _A. To 254 _R ). Each receiver 254 conditions (eg, filters, amplifies, and downconverts) each received signal, digitizes the conditioned signal to provide samples, and generates a corresponding "received" symbol stream. The samples are further processed to provide. Then, the receiving and RX data processor 260 N _R received symbols streams from N _R receivers 254 based on a particular receiver processing technique to provide N _T of "detected" symbol streams Process. RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover traffic data for the data stream. Processing by the RX data processor 260 is complementary to the processing performed by the TX MIMO processor 220 and the TX data processor 214 of the transmitter system 210. Processor 270 typically determines periodically which coding matrix to use (discussed below). Processor 270 formulates a reverse link message comprising a matrix index portion and a rank value portion. The reverse link message may include various types of information regarding the communication link or the received data stream, or a combination thereof. The reverse link message is then processed by the TX data processor 238 which receives traffic data for the multiple data streams from the data source 236, modulated by the modulator 280, and the transmitters 254 _A. To 254 _R ), and is sent back to the transmitter system 210.

In transmitter system 210, a modulated signal from receiver system 250 is received by antenna 224, conditioned by receivers 222, demodulated by demodulator 240, and receiver system 250. Is processed by the RX data processor 242 to extract the reverse link message sent by < RTI ID = 0.0 > Processor 230 then determines which pre-coding matrix to use to determine the beamforming weights and processes the extracted message.

개의 독립 채널들로 분해될 수 있으며, 여기서

이다.

개의 독립 채널들의 각각은 차원(dimension)에 대응한다. The single-user MIMO mode of operation corresponds to the case where a single receiver system 250 communicates with the transmitter system 210 as described in FIG. 2 and in accordance with the operation described above. In such a system, the N _T transmitters (224 ₁ -224 _T) (also known as addition, RX antenna) (known search as TX antennas) and the N _R receivers (252 ₁ -252 _R) is the matrix for wireless communication Form a channel (eg, a Rayleigh channel or a Gaussian channel). SU-MIMO channels are described by an N _R xN _T matrix of random complex numbers. The rank of the channel is equal to the algebraic rank of the N _R × N _T channel. In space-time or space-frequency coding, the rank is equal to the number of layers or data streams transmitted over the channel. The rank is at most equal to min {N _T , N _R }. The MIMO channel formed by the N _T transmit and N _R receive antennas is referred to as spatial channels

Into independent channels, where

to be.

Each of the four independent channels corresponds to a dimension.

에서 다음과 같이 모델링될 수 있다.In one aspect, symbols transmitted / received with OFDM

Can be modeled as:

수식(1)

Formula (1)

는 수신된 데이터 스트림이고

벡터이며,

는 톤

에서 채널 응답

매트릭스(예컨대, 시간-종속 채널 응답 매트릭스

의 푸리에 변환)이며,

는

출력 심볼 벡터이며,

는

잡음 벡터(예컨대, 부가 백색 가우스 잡음(additive white Gaussian noise)이다. 프리코딩은

계층 벡터를

프리코딩 출력 벡터로 변환시킨다.

는 송신기(210)에 의하여 전송된 데이터 스트림들(계층들)의 실제 수이며,

는 채널 상태들 및 단말에 의하여 보고된 랭크에 적어도 부분적으로 기초하여 송신기(예컨대, 기지국(140))의 판단으로 스케줄링될 수 있다.

가 적어도 하나의 다중화 방식과 송신기에 의하여 적용된 적어도 하나의 프리-코딩(또는 빔포밍) 방식의 결과치이다. 부가적으로,

는 각각의 데이터 스트림

을 전송하기 위하여 송신기(210)가 할당해야 하는 전력량을 결정하는 전력 이득 매트릭스로 컨벌루션된다는 것에 유의해야 한다. 전송시 사용되는 순전력은 무선 통신들에서 송신기의 전송 전력의 조절된 값에 의하여 상한이 한정된다. Here you go,

Is the received data stream

Vector,

Tons

Channel response

Matrix (e.g., time-dependent channel response matrix

Fourier transform)

Is

Output symbol vector,

Is

Noise vector (e.g., additive white Gaussian noise).

Layer vector

Convert to precoding output vector.

Is the actual number of data streams (layers) transmitted by transmitter 210,

May be scheduled at the discretion of the transmitter (eg, base station 140) based at least in part on the channel conditions and the rank reported by the terminal.

Is the result of at least one multiplexing scheme and at least one pre-coding (or beamforming) scheme applied by the transmitter. In addition,

Is the respective data stream

It is to be noted that the transmitter 210 is convolved with a power gain matrix that determines the amount of power that the transmitter 210 should allocate to transmit. The net power used in transmission is limited by the adjusted value of the transmitter's transmit power in wireless communications.

일때, 시스템은 여기에서 제시된 하나 이상의 양상들에 따라 무선 통신 환경에서 섹터 통신을 위하여 제공할 수 있는 단일-입력 단일-출력(SISO) 시스템으로 감소한다. In system 200 (FIG. 2),

Is reduced to a single-input single-output (SISO) system that can provide for sector communication in a wireless communication environment in accordance with one or more aspects presented herein.

과 그 자신의 랭크와 함께 응답 매트릭스

(

=P, U 및 S)를 가진다. 셀내 간섭은 기지국(140)에 의하여 서비스되는 셀내에 존재하는 다수의 사용자들로 인하여 발생할 수 있다. 비록 도 3에 3개의 단말들이 기술되었을지라도, MU-MIMO 시스템은 이하에서 인덱스 k로 표시된 임의의 수의 단말들을 포함할 수 있다.3 shows an example multi-user MIMO system 300 in which UEs 120 _P , 120 _U , 120 _S are in communication with a base station 140. The base station has N _T of TX antennas, each UE has a plurality of RX antennas, i.e. UE has a _P s _P N of antennas (252 ₁ -252 _P), the UE is _U N _U antennas ( 252 ₁ has a _U -252), UE has the _s s _s N antennas (252 ₁ -252 _s). Communication between the terminals and the base station is performed via the uplinks 315 _P , 315 _U , 315 _S. Similarly, downlinks 310 _P , 210 _U , 210 _S respectively facilitate communication between base station 140 and terminals UE _P , UE _U , UE _S. In addition, the communication between each terminal and the base station is implemented in substantially the same way through substantially the same components as described in FIG. 2 and the corresponding detailed description. Since the terminals may be located at substantially different locations within the cell served by the base station 140, each terminal 120 _P , 120 _U , 120 _S itself has a matrix channel.

And the response matrix with his own rank

(

= P, U and S). Intracell interference may occur due to a number of users residing in the cell served by the base station 140. Although three terminals are described in FIG. 3, the MU-MIMO system may include any number of terminals indicated by index k below.

에서 그리고 사용자 k에 대하여 다음과 같이 모델링될 수 있다.In one aspect, symbols transmitted / received with OFDM are tones

And for user k can be modeled as follows.

수식(2)

Formula (2)

가 덧셈으로부터 제외된다는 것을 지시한다. 수식에서 항들은 송신기(예컨대, 기지국(140))에 의하여 셀내의 다른 사용자들에게 전송된 심볼들의 사용자 k에 의한 수신(채널 응답

)을 나타낸다. 셀간 간섭은 채널 상태들을 적어도 부분적으로 결정하며, 따라서 MU-MIMO 동작에서 결정된, 송신기(CSIT)의 채널 상태 정보가 본래 앞서 논의된 SU-MIMO 동작에서 CSIT와 다를 수 있다는 것이 명백할 것이다. Here, the symbols have the same meaning as in Equation (1). The other user interference of the signal received by user k due to multi-user diversity is modeled by the second term on the left side of equation (2). The prime sign (') symbol is the transmitted symbol vector

Indicates that is excluded from addition. The terms in the equation are received by user k of symbols sent by the transmitter (e.g., base station 140) to other users in the cell (channel response

). Inter-cell interference determines channel conditions at least in part, so it will be apparent that the channel state information of the transmitter (CSIT), determined in the MU-MIMO operation, may differ from the CSIT inherently in the SU-MIMO operation discussed above.

)에 대하여 6개의 심볼들이 슬롯마다 수용되는 반면에 짧은 CP(예컨대, 4.69

)에 대하여 7개의 심볼들이 수용된다. 코드 심볼들은 서브-프레임에서 이용가능한 심볼들중 하나 이상을 점유할 수 있다. 더욱이, 전송된 시퀀스 코드는 P-SCH에 대하여 N-심볼 길이, S-SCH에 대하여 M-심볼 길이, 그리고 BCH에 대하여 L-심볼 길이를 가질 수 있으며, 여기서 N, M, L은 다르거나 또는 동일할 수 있는 정수들이다. 다이어 그램들(410, 420, 430)은 다른 "차수들(order)"을 가진 N-심볼 스트림들(N=M=L)의 예시적인 경우들을 기술하며, 여기서 차수는 각각의 프레임으로 전송된 심볼들의 수에 의하여 주어진다. 전송 구성의 차수는 검출의 효율성에 영향을 미칠 수 있는데, 고차 전송(high-order transmission)은 보다 빠른 검출을 가능하게 하여 저차 구성(low-order configuration)보다 빠른 셀 동기포착을 가능하게 할 수 있으나, 기지국(예컨대, 기지국(140))이 P-SCH, S-SCH 및 BCH 코드들과 같은 동기포착 코드들을 연속적으로 전송하기 때문에, 고차 구성은 동기포착이 달성된후에는 바람직하지 않을 수 있다. 동기포착 코드들은 서비스 셀의 단말들(예컨대, 사용자 장비(120))이 비동기적으로 스위치-온(switch-on)되거나 또는 적절한 동기화없이 주변 셀로부터 셀에 비동기적으로 진입하기 때문에 연속적으로 전송된다는 것이 인식되어야 한다.4 shows example diagrams 410, 420, 430 showing transmission configurations of P-SCH codes, S-SCH and BCH codes. As mentioned above, transmission is accomplished in 10 ms radio frames with sub-frames of 1 ms (not shown) and slots of 0.5 ms. The symbols are sent in their respective slots. For 3G LTE the number of symbols in each sub-frame depends on the length of the CP, i.e. the long CP (e.g. 16.67)

6 symbols are accommodated per slot, whereas a short CP (e.g., 4.69)

7 symbols are accepted. Code symbols may occupy one or more of the symbols available in a sub-frame. Moreover, the transmitted sequence code may have an N-symbol length for the P-SCH, an M-symbol length for the S-SCH, and an L-symbol length for the BCH, where N, M, L are different or Are integers that can be the same. Diagrams 410, 420, 430 describe example cases of N-symbol streams (N = M = L) with different “orders”, where the order is transmitted in each frame. It is given by the number of symbols. The order of the transmission configuration may affect the detection efficiency. High-order transmission may allow for faster detection, which may result in faster cell acquisition than the low-order configuration. Because the base station (e.g., base station 140) continuously transmits acquisition codes such as P-SCH, S-SCH and BCH codes, a higher order configuration may not be desirable after acquisition is achieved. Acquisition codes are transmitted continuously because the terminals of the serving cell (eg, user equipment 120) are switched on asynchronously or asynchronously enter the cell from the neighboring cell without proper synchronization. Should be recognized.

만큼 지연되어 먼저 전송되며, S-SCH 코드 심볼은 시간

만큼 지연되어 후속하며, BCH 코드 심볼은 나중에

에 전송된다. BCH 심볼 및 무선 프레임 경계사이의 시간은

이다. 시간들

및

은 프레임 및 서브-프레임 경계의 검출을 용이하게 하기 위하여 설계 파라미터들로서 사용될 수 있다는 것에 유의해야 한다. 전송 구성(410)에서, 코드 길이는 무선 프레임 번호에 비례한다(예컨대, 3×N 심볼들은 N 개의 무선 프레임들로 전송된다). 다이어그램(420)은 차수-2 구성을 도시하며, 2개의 심볼들은 각각의 프레임으로 전송되며 심볼들은 다음 프레임들을 순환적으로 점유한다. 이러한 전송 구성에서, 전송된 심볼들은 프레임들과 같은 크기가 아니다. 따라서, 정보는 이하에 기술되는 바와같이 3-채널 코드들을 사용하여 특정 셀 정보를 전송하기 위하여 리던던트적으로(redundantly) 전송될 수 있다. 차수-1 구성 전송은 P-SCH, S-SCH 및 BCH에 대한 코드들의 순차 전송에 대응한다. 차수-1 전송에서 고차들보다 느릴 수 있는 셀 동기포착후에, 이러한 전송은 차수-3 구성보다 더 효율적으로 대역폭을 사용할 수 있다. 단일 검출 컴포넌트(예컨대, 검출 컴포넌트(122))를 가진 단말(예컨대, 사용자 단말(120))에서, 셀 동기포착은 계층적으로(hierarchically) 이루어질 수 있으며, 예컨대 P-SCH 코드로 반송된 정보가 먼저 획득된후, S-SCH 코드로 반송된 정보가 획득되고 그 다음에 BCH로 반송된 정보가 획득된다는 것이 인식되어야 한다. 다이어그램(410, 420, 430)과 다른 전송 구성들이 가능하며 본 발명의 범위내에 있다는 것이 인식되어야 한다.Diagram 410 describes an order-3 transmission configuration, where one symbol of the P-SCH code, one symbol of the S-SCH, and one symbol of the BCH are transmitted in each frame. P-SCH code symbols are timed for the radio frame boundary

Delayed by one and transmitted first, with the S-SCH code symbol being time

Delayed by and followed by a BCH code symbol

Is sent to. The time between the BCH symbol and the radio frame boundary

to be. Times

And

It should be noted that may be used as design parameters to facilitate detection of frame and sub-frame boundaries. In transmission configuration 410, the code length is proportional to the radio frame number (e.g., 3xN symbols are transmitted in N radio frames). Diagram 420 shows an order-2 configuration in which two symbols are sent in each frame and the symbols cyclically occupy the next frames. In this transmission configuration, the transmitted symbols are not the same size as the frames. Thus, information can be transmitted redundantly to transmit specific cell information using three-channel codes as described below. Order-1 configuration transmission corresponds to sequential transmission of codes for P-SCH, S-SCH, and BCH. After cell acquisition, which may be slower than higher orders in order-1 transmission, this transmission may use bandwidth more efficiently than the order-3 configuration. In a terminal (eg, user terminal 120) with a single detection component (eg, detection component 122), cell acquisition may be hierarchically, eg, information conveyed in a P-SCH code may be It should be recognized that after the information is first obtained, the information carried in the S-SCH code is obtained and then the information carried in the BCH is obtained. It is to be appreciated that the diagrams 410, 420, 430 and other transmission configurations are possible and within the scope of the present invention.

5A and 5B illustrate two schemes for bandwidth utilization for transmitting P-SCH, S-SCH and BCH code sequences for exemplary system bandwidths (1.25 MHz, 5 MHz, 10 MHz and 20 MHz) in accordance with an aspect. 510 and 520 are shown. Acquisition codes (e.g., codes that carry operating cell information to a wireless device such as user equipment 120) may be used for (a) the fact that the system bandwidth is not known until the system is acquired, (b) the specifics of the information carried. Due to the nature, and (c) the possibility of carrying information using short codes (small N), may use part of the system bandwidth. Thus, the remainder of the bandwidth (eg, user data, channel quality indicator channel, acknowledgment channel, load indicator channel, etc.) can be used during user and station data transmission. In one aspect, sync channels (both primary and secondary) and broadcast channel may be transmitted at 1.25 MHz, regardless of system bandwidth (method 510). As an example, in 3G LTE, 83 sub-carriers can be accommodated in this frequency interval. In another aspect, the synchronization channel may be transmitted at 1.25 MHz regardless of the system bandwidth, while the broadcast channel may be transmitted at 1.25 MHz when the system bandwidth is 1.25 MHz and at 5 MHz when the BW is wide. 520).

6 illustrates information transmitted by a synchronization channel and a broadcast channel according to one aspect. As shown in step 610, the code sequence of the SCH includes (1) OFDM symbol boundary detection, (2) coarse frequency synchronization, (3) radio frame boundary detection, (4) cyclic prefix (CP) timing, (5) cell identifier, and (6) BCH bandwidth indicator. In particular, the primary synchronization channel can be used for coarse frequency synchronization and can also be used for OFDM symbol, slot and sub-frame time boundaries. In a suitable transmission configuration, the secondary sync channel can be used to detect 5 ms 1/2 radio frames and 10 ms radio frame boundaries. As shown in step 620, the code sequences for the BCH may be used for other system information such as (a) CP timing, (b) system bandwidth, and (c) base station antenna configuration, neighbor cell information, and so forth. Frequency synchronization as well as timing information may be obtained by the correlator 128 and the processor 124 of the detection component 122. Repeated sequences transmitted over the downlink 160 are detected by the correlator 128 and the timing metric is calculated by the processor 124. Timing and frequency synchronization methods, such as the Moose method, the Van De Beenk method and the Schmidl method, propose specific code sequences with repetitive sections of the transmitted code to estimate the frequency offset as well as frame and subframe boundaries. It should be appreciated that other methods are possible for symbol boundary detection, CP period and frequency synchronization. After timing and frequency synchronization, code sequences carrying system information (eg, cell ID, BCH and system bandwidth, antenna configuration of the base station) may be demodulated by the FFT component 130 of the detection component 122, and cell synchronization Acquisition can be completed.

The transmission information listed in panels 610 and 620 may be achieved through a combination of P-SCH, S-SCH and BCH code sequences. 7A, 7B and 7C describe cell acquisition sequences in accordance with aspects of the present invention. In one of these aspects, acquisition sequence 725 (FIG. 7A), at 730, acquires an OFDM symbol boundary through (timing or correlation) detection of a primary synchronization code (PSC) sequence, The P-SCH is transmitted at 1.25 MHz (Figure 5A). It should be recognized that all cells transmit the same PSC sequence, and as mentioned above, the sequence may be a generalized chirp-like sequence (eg, Zadoff-Chu sequence), Walsh-Hadamar sequence, gold code sequence, M- Sequence, pseudonoise sequence, etc.), but is not limited thereto. Frequency synchronization is performed at 730. Next, at 735, the radio frame boundary and cell ID are detected via a secondary sync code (SSC) sequence, and the S-SCH is transmitted at 1.25 MHz (FIG. 5A). In one aspect, to carry cell ID information, sequences sent on the S-SCH are selected to indicate all possible 512 hypothesis (number of cell IDs) in 3G LTE. Note that each cell ID code can be transmitted in 9 bits. At 740, CP duration, downlink system bandwidth, and other system information are obtained through demodulation of the broadcast channel transmitted at 1.25 MHz (FIG. 5A). It should be appreciated that CP timing can be detected after the symbol boundary is detected. In addition, the CP timing is such that the CP time-guard interval is added to the receiver (e.g., by the processor 122) after the frequency-domain modulation is converted to the time-domain symbol stream (IFFT) and the CP is pre-done during data detection. It is essential in OFDM to successfully demodulate OFDM data symbols because it is removed in the -FFT state.

In another aspect, acquisition sequence 750 obtains an OFDM symbol boundary and CP timing during decoding of the P-SCH sequence, at 755. Two sequences transmitted at 1.25 MHz (Figure 5B) can be used to achieve this acquisition. In order to reduce intersymbol interference, the sequences may be orthogonal, such as Walsh-Hadamar code, but other sequences may be considered within the scope of the present invention. As in the sequence 725 described above, every cell transmits one of two PSC sequences. It should be appreciated that demodulation of data other than training or pilot sequences may be achieved upon detection of the P-SCH. Frequency synchronization is also performed at 755. At 760, an S-SCH sequence transmitted at 1.25 MHz (FIG. 5B) is designated to describe 1024 hypotheses that may include 512 cell ID codes. An indicator of the BCH bandwidth, which can be 1.25 MHz or 5 MHz, is obtained. At 765, BCH code sequences are demodulated, and these sequences carry system information, such as station antenna configuration, neighbor cell IDs, and the like. The amount of information transmitted on the BCH may be proportional to the channel bandwidth. In addition, the sequence 750 allows for variable transmission bandwidth for the broadcast channel, so that the communication overhead can remain substantially the same across all system bandwidths. In addition, it should be appreciated that the terminal (eg, user equipment 120) has a small number of BCH demodulation hypotheses due to CP period detection in P-SCH code detection.

를 가진 시스템에 대하여 시스템 서브캐리어들의 전체 이용가능 세트의 비분할이 효율적으로 사용되며, 3의 재사용, 예컨대

를 가진 시스템에 대하여 3개의 서브세트의 이용가능 시스템 서브캐리어들의 분할이 사용된다. 예로서, 3G LTE에서,

를 가진 무선 전송 시스템은 400개의 서브캐리 어들의 2개의 세트와 401개의 서브캐리어들의 하나의 세트로 분할될 수 있다. S-SCH로 전송된 시퀀스들은 512개의 가설들(ID들이라 지칭함)을 운반하도록 지정된다. 그럼에도 불구하고, 셀 ID는 P-SCH로 셀 ID를 위하여 필요한 9비트의 일부와 S-SCH로 나머지 비트를 전송함으로서 P-SCH 및 부분적으로 S-SCH를 통해 전송될 수 있다는 것이 인식되어야 한다. 도면부호 790에서, BCH 코드 시퀀스들은 시스템 대역폭에 따라 1.25MHz 또는 5MHz로 전송될 수 있으며(도 5B), CP 기간, 시스템 BW 정보 및 다른 시스템 정보를 운반한다. In another aspect, acquisition sequence 775 may alternatively combine the information (FIG. 6) transmitted by the SCH and BCH. That is, two P-SCH code sequences transmitted at 1.25 MHz, which may be orthogonal to each other, aid in symbol timing detection and BCH BW indication. In addition, frequency synchronization is performed. S-SCH channel code sequences are transmitted at 1.25 MHz, and frequency reuse is applied to these sequences. Frequency reuse contemplates using different subcarrier sets among the total available subcarriers for transmission from adjacent or neighboring cells. Thus, sequence frequency (tone) mapping may depend on the reuse factor. In one aspect, reuse of 1, such as

For a system with a non-partition of the entire available set of system subcarriers is effectively used and reuse of 3, for example

For a system with a split of three subsets of available system subcarriers are used. For example, in 3G LTE,

A wireless transmission system with a can be divided into two sets of 400 subcarriers and one set of 401 subcarriers. Sequences sent on the S-SCH are designated to carry 512 hypotheses (referred to as IDs). Nevertheless, it should be appreciated that the cell ID can be transmitted over the P-SCH and partly over the S-SCH by transmitting some of the 9 bits needed for the cell ID to the P-SCH and the remaining bits to the S-SCH. At 790, BCH code sequences may be transmitted at 1.25 MHz or 5 MHz depending on system bandwidth (FIG. 5B) and carry CP duration, system BW information and other system information.

It should be appreciated that after initial cell acquisition is complete, the terminal (eg, user equipment 120) may use the achieved frequency synchronization to perform neighbor cell search. In a time-synchronous system, a terminal that completes cell acquisition processes time synchronization with neighbor cells, so neighbor cell detection is used to identify other important information such as cell ID of neighbor cells and antenna configuration of neighbor cell transmitters. Is reduced. Instead, in the case of an asynchronous system, the terminal needs to repeat the full cell search for neighboring cells. It should also be appreciated that the code sequences sent by the base station in connection with cell detection may be stored in a memory (eg, memory 126) in the terminal performing cell acquisition. This information may allow the terminals to seamlessly perform cell search under multiple acquisition sequences (eg, acquisition sequences 725, 750, 775).

Successful discovery acquisition by the terminal depends on the channel conditions (eg SNR, SINR). Terminals with poor channel quality indicators fail cell acquisition and thus fail to form functional wireless communication links with an access point (eg, base station 140). In order to increase the likelihood that the terminal will succeed in cell acquisition (synchronization), the cell search information may be relayed from the synchronized terminal to the terminals with poor channel conditions. FIG. 8A shows a cell in two asynchronous terminals 815 and 825 where terminal 120 having completed cell acquisition (synchronization) from base station 140 in serving cell 810 may be affected by poor channel conditions. A system 800 for relaying information is shown. The example service cell 810 has a hexagonal shape, but it should be appreciated that the cell shape is dictated by a particular tiling that covers a particular service area. During cell acquisition, terminal 120 stores the P-SCH, S-SCH, and BCH code sequences in a memory (eg, memory 126). As noted above, these sequences carry operational cell information that causes the wireless device (eg, terminal 120) to form active communication links 850 with the base station (eg, base station 140). Cell acquisition sequences (eg, sequences 725, 750, 775) are relayed to terminal 815 over link 860 ₁ and to terminal 825 over link 860 ₂ for synchronization. The terminals can then be synchronized with the access point (eg, base station 140) regardless of the channel conditions. In system 800, it should be appreciated that terminal 120 continuously transmits sync code sequences in a manner substantially similar to that performed by the base station. In addition, when relaying sync code sequences of P-SCH, S-SCH and BCH, the bandwidth used need not be the same bandwidth as used by the base station (eg, 1.25 MHz or 5 MHz).

동안 특정 스케줄링된 시간들, 예컨대

에 정보를 중계할 수 있다. 이러한 시간들 및 시간 간격들은 단지 예시적이며 중계는 많은 다른 개별 시간들 및 간격들에서 이루어질 수 있다는 것이 인식되어야 한다. 이러한 시간들은 단말의 메모리(예컨대, 메모리(126))에 저장될 수 있거나 또는 단말에 특정될 수 있으며, 시간 간격은 전력 자원들, 안테나 구성 등과 같은 단말 구조에 따라 다른 단말들에 대하여 다른 값들을 가정한다. 단말의 프로세서(예컨대, 프로세서(124))는 셀 정보의 중계가 트리거링되는 시간들을 스케줄링할 수 있으며, 또한 정보의 중계를 트리거링할 수 있다. 중계 시간간격이 시간에 특정할 수 있는 경우에, 셀 정보의 중계는 비동기로 이루어질 수 있으며, 단말 다이버시티(예컨대, 서비스 셀내에 여러 동기된 단말들의 존재)은 기지국과의 불량한 통신 상태들이 지속되는 동안 낮은 SNR을 가진 단말들이 계속해서 동기하여 데이터를 수신할 수 있도록 할 수 있다. 전자기 방사의 전력 소비가 방사원으로부터의 거리의 제곱에 반비례하여 감소할 수 있다는 것이 인식되어야 한다. 따라서, SNR은 단말 및 기지국사이에서 불량할 수 있으며, 또한 단말들이 지리적으로 근접할때 단말 및 중계 단말(예컨대, 단말(120), 단말(835))사이에서 상당히 높을 수 있다. Relaying the synchronization information may increase the complexity of the structure of the terminal (eg, the terminal 120) in addition to increasing communication overhead. To mitigate the increase in communication overhead, the terminal may, for example, for certain time intervals, for example, as shown in diagram 850.

During certain scheduled times, such as

You can relay the information to. It should be appreciated that these times and time intervals are exemplary only and that relaying may occur at many different individual times and intervals. These times may be stored in the terminal's memory (eg, memory 126) or may be specific to the terminal, the time interval being different for different terminals depending on the terminal structure such as power resources, antenna configuration, etc. Assume The processor of the terminal (eg, the processor 124) may schedule times when the relay of cell information is triggered, and may also trigger the relay of information. In the case where the relay time interval can be specified in time, the relaying of cell information can be made asynchronously, and terminal diversity (eg, the presence of several synchronized terminals in a serving cell) can result in poor communication conditions with the base station. While the terminal with the low SNR can continue to receive data in synchronization. It should be appreciated that the power consumption of electromagnetic radiation can be reduced in inverse proportion to the square of the distance from the radiation source. Thus, the SNR may be poor between the terminal and the base station, and may also be significantly higher between the terminal and the relay terminal (eg, terminal 120, terminal 835) when the terminals are geographically close.

)을 트리거링할 것을 지시하는 기지국으로부터 파일럿 시퀀스를 수신할 수 있다. 기지국내의 인공지능 컴포넌트는 서비스 셀내의 동기된 단말들의 순간적 또는 시간적 및/또는 공간적으로 평균된 채널 품질 지시자들에 기초하여 셀 정보를 중계할 것을 요청하는 파일럿 신호들을 전송할때를 통계 기반 분석 및/또는 유틸리티 분석을 통해 추론할 수 있다. "중계 요청" 파일럿 신호를 전송한 다음에 기지국이 오버헤드를 감소시키기 위하여 다운링크를 통해 셀 정보를 전송하는 것을 일시적으로 중지시킬 수 있다는 것에 유의해야 한다. In addition to, or alternatively, relaying cell information at a predetermined time, the synchronized terminal (eg, the terminal 120) may have a relay period (eg,

May receive a pilot sequence from a base station instructing to trigger (). The artificial intelligence component in the base station may perform statistical based analysis and / or when transmitting pilot signals requesting relay of cell information based on instantaneous or temporal and / or spatially averaged channel quality indicators of synchronized terminals in the serving cell. Or utility analysis. It should be noted that after transmitting the "relay request" pilot signal, the base station may temporarily stop transmitting cell information on the downlink to reduce overhead.

While the first relay terminal (e.g., terminal 120) relays information for a predetermined period of time, the second synchronized relay terminal (e.g., terminal 835) relays the data and then other terminals continue to transmit the data. It should be recognized that it can be relayed. Each of the relay terminals may have a time-dependent relaying profile as described by diagram 850 of FIG. 8B. In one aspect, cell-search relaying may be used in environments where voice, video, or data wireless transmission or any combination thereof is mission-critical. In one aspect, such an environment may be a downtown battlefield where substantial non-interrupted access to the enemy intelligence is key and the SNR is typically low inside buildings and in institutions. The base station can be integrated into a military vehicle with a transceiver for wireless communication that provides logistical support to small group troops with mobile terminals. When troops perform their mission, each of the mobile terminals with a sufficient level of SNR can relay synchronization information as troops enter and exit buildings and institutions, thus deciding critically low SNR areas without the need for cell acquisition. You can enter or exit.

에 대한 미리 결정된 동작 사이클(예컨대, 시간, 일(day))동안 특정 시간들, 예컨대

에서 활성화될 수 있다. 간격들

외의 시간들에서, 모든 서브캐리어들을 사용하는 동작이 재시작된다. 이러한 시간-종속 동작은 도 9C의 예시적인 다이어그램(950)에 도시되어 있다. 일 양상에서, 주파수 재사용 동작으로의 스위칭은 주파수 재사용으로 동작하는 기지국들(예컨대, BS₁, BS₂, BS₃)의 각각에 제공될 수 있는 프로세서들에 의하여 결정된다. 특정 시간들

및 시간 간격들

은 주파수 재사용으로 동작하는 기지국들의 각각에 위치한 메모리들에 저장될 수 있다. 9A is a system 900 for acquisition with respect to when the cells are operating in a frequency re-use terminal 920 of the downlink (960 ₁ -960 _3), adjacent cells (940 _1, 940 _2, 940 ₃₎ through the Illustrated. In multi-cell synchronization based on frequency reuse, to prevent performance degradation (eg, reduced throughput) due to the use of a subset of subcarriers instead of all subcarriers available at each base station (showing 12 tones). One exemplary diagram 925 (see FIG. 9B), multi-cell operation using frequency reuse can be implemented in specific periods, such as

Specific times during a predetermined operating cycle (e.g., time, day) for

It can be activated at. Intervals

At other times, the operation using all subcarriers is restarted. This time-dependent operation is shown in the example diagram 950 of FIG. 9C. In one aspect, switching to frequency reuse operation is determined by processors that may be provided to each of the base stations (eg, BS ₁ , BS ₂ , BS ₃ ) operating with frequency reuse. Specific times

And time intervals

May be stored in memories located in each of the base stations operating with frequency reuse.

It shows the structure of a system 1000 that at the same time acquisition for a number of cells, with - Figure 10 is a user equipment 1020 during frequency reuse operation cell emitters (1040 _L 1040 _1). In selecting a subcarrier set, a base station (eg, base station 1040 _K , where 1 <K <L) sub-carriers the sync channel (P-SCH, S-SCH) and broadcast channel cell-acquisition code sequences. Maps to the selected set of bits and sends these codes to the center of the selected subcarrier subset. Terminal 1040 _K may use terminal-specific bandwidth for the selected subcarriers. In one aspect, this bandwidth is minimum between 1.25 MHz and the frequency spacing of the selected subcarriers. The user equipment 1020 has a structure that allows the user equipment to simultaneously detect a set of L data streams. Such L streams correspond to the OFDM symbol transmitted over the L subsets of subcarriers consistent with frequency reuse of order L that used for the base stations (1040 ₁ -1040 _L) is in a call. Accordingly, the user terminal 1020 may simultaneously acquire L cells. The structure of the terminal 1020 may include a processor 1022, memory 1024, and a detection component (1026 ₁ -1026 _L). Each of these detection components operates in substantially the same manner as detection component 122 (see FIG. 1). In another aspect, multi-cell acquisition using frequency reuse can be achieved by all-terminals-off policies, such as courts, any hospital areas, etc., while multiple terminals are nearly simultaneously (e.g., while taxiing the plane after landing). Can be used in certain sectors that can be synchronized.

Given the example systems presented above, methods that may be implemented in accordance with the presented subject matter will be more readily understood with respect to the flow charts of FIGS. 11-13. While the methods are presented as a series of block diagrams to simplify the description, the claimed subject matter can be made in a different order and / or concurrently with other blocks shown herein, so that the number of blocks or It should be understood that it is not limited by order. Moreover, not all presented blocks may be necessary to implement the methods presented below. It should be appreciated that the functionality associated with the blocks may be implemented by software, hardware, a combination thereof, or any other suitable means (eg, apparatus, system, process, component,...). In addition, it should be appreciated that the methods set forth below and throughout this specification may be stored on an article of manufacture for transferring and transferring these methods to various devices. Those skilled in the art will appreciate that a method may be alternately represented, for example, as a series of interrelated states or events in a state diagram.

11 is a flowchart illustrating a method of performing cell acquisition. First, P-SCH, S-SCH, and BCH code sequences carrying cell information are received. Such information may include other system information such as OFDM symbol boundaries, frequency synchronization, radio frame boundaries, cell identifiers, cyclic prefix timing, BCH bandwidth indicators, system bandwidth, and base station antenna configuration, neighbor cell information, and the like. In step 1120 the code sequences are processed, eg, correlation timing metrics are calculated. In one aspect, this calculation may be performed by a processor at the user equipment, such as processor 124. In step 1130, the aforementioned cell information is extracted.

12 is a flowchart illustrating a method of relaying cell synchronization information. In step 1210, cell search is performed in accordance with one or more aspects presented herein (eg, FIG. 7A, 7B or 7C). In step 1220, code sequences for primary and secondary synchronization channels and a broadcast channel are stored. In one aspect, the storage may be implemented in the memory of the terminal that performed the cell search in step 1210. Such memory may be memory 126. The relaying of cell information through the transmission of stored code sequences is performed at step 1230. In one aspect, the bandwidth used to transmit the respective code sequences is determined by the capabilities of the user equipment to perform information relay, which bandwidth is used by the base station to transmit the code sequence to the relaying user equipment. It may be different from the bandwidth.

13A / 13B are a flow diagram of a method for transmitting / receiving cell information using frequency reuse in a cellular wireless communication system. Referring to FIG. 13A, in step 1310, frequency reuse of order L is determined. In an aspect, in OFDMA, such a frequency re-use is the L cell transmitters to select the L subsets of subcarriers out of the total set of appropriate available subcarriers in the system bandwidth (e.g., a base station (1040 ₁ -1040 _L ), Such L subsets can be provided. This decision is usually the operator's decision according to a wireless communication standard (eg, 801.11b, 801.11g, 3G LTE). In step 1320, the cell information is transmitted using the determined L subcarrier subsets. Referring to FIG. 13B, at step 1355, cell information is received from L subsets of subcarriers. In one aspect, the information is detected by a user equipment (e.g., user equipment 1020) with a suitable structure to detect the P-SCH and S-SCH for all L code sequence transmissions and simultaneously demodulate the BCH. . In step 1365, cell information is extracted from each of the L subsets of subcarriers.

Referring now to FIG. 14, a system 1400 is provided that enables receiving code sequences of primary and secondary sync channel symbols. System 1400 may be at least partially disposed in a wireless device (eg, user equipment 120) and may be functional blocks that represent functions executed by a processor or electronic machine, software, or a combination thereof (eg, firmware). May include functional blocks. In particular, system 1400 includes a logical grouping 1410 of electronic components that can act in conjunction. In one aspect, logical grouping 1410 carries at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitates orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection. And an electronic component 1415 that receives a code sequence of primary sync channel symbols (see FIG. 4). Moreover, logical grouping 1410 receives an electronic component 1425 that receives one or more code sequences of secondary sync channel symbols that carry at least one of a radio frame boundary, a portion or all of a cell identification code, and an indicator of broadcast channel bandwidth. ). In addition, logical grouping 1410 includes an electronic component 1435 that receives a code sequence of broadcast channel symbols (eg, see FIG. 4) that carries at least one of cyclic prefix timing and wireless system bandwidth. The electronic component 1435 receives an electronic component 1438 that receives a code sequence of sync channel symbols transmitted at 1.25 MHz (see FIG. 5A) and a code sequence of broadcast channel symbols transmitted at 1.25 MHz or 5 MHz (see FIG. 5B). Note that it further includes a receiving electronic component 1441.

Additionally, system 1400 may store instructions for executing functions associated with electronic components 1415, 1425, 1335, 1438, 1441 as well as data that may be generated during execution of these functions. ) May be included. While shown as being external to memory 1450, it is to be understood that one or more of electronic components 1415, 1425, 1335, 1438, 1441 may exist within memory 1450.

What has been presented above includes examples of one or more aspects. Of course, it is not possible to describe every conceivable combination of components or methods to describe the foregoing aspects, but one of ordinary skill in the art will recognize that many further combinations and substitutions of the various aspects are possible. Accordingly, the presented aspects are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.

Claims (41)

A device operating in a wireless communication environment, A primary synchronization channel, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection A processor configured to receive a code sequence of; And A memory coupled to the processor, the memory storing data; Device. The apparatus of claim 1, wherein the processor is configured to receive one or more code sequences of a secondary synchronization channel, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth. . 2. The apparatus of claim 1, wherein the processor is configured to receive a code sequence of a broadcast channel that carries at least one of cyclic prefix timing and wireless system bandwidth. 2. The apparatus of claim 1, wherein the processor is configured to relay the code sequence to a terminal of a wireless communication system that has failed to obtain cell information from a cell base station. 5. The apparatus of claim 4, wherein the processor is configured to schedule a time for triggering relaying of the code sequence. 6. The apparatus of claim 5, wherein the data stored in the memory includes a scheduled time for triggering relay of the code sequence. A device operating in a wireless communication environment, Code sequence of the primary sync channel, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection A processor configured to transmit; And A memory coupled to the processor, the memory storing data; Device. 8. The apparatus of claim 7, wherein the processor is configured to transmit one or more code sequences of a secondary synchronization channel carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth. . 8. The apparatus of claim 7, wherein the processor is configured to transmit a code sequence of a broadcast channel that carries at least one of cyclic prefix timing and wireless system bandwidth. 8. The apparatus of claim 7, wherein the processor is configured to transmit the code sequence at 1.25 MHz. 10. The processor of claim 9, wherein the processor is configured to transmit the code sequence at 1.25 MHz when the system bandwidth BW is less than 5 MHz and to transmit the code sequence at 5 MHz when the BW is greater than or equal to 5 MHz. , Device. 8. The apparatus of claim 7, wherein the processor is configured to send a request to relay the code sequence. The apparatus of claim 8, wherein the processor is configured to send a request to relay the one or more code sequences. 10. The apparatus of claim 9, wherein the processor is configured to send a request to relay the code sequence. 13. The apparatus of claim 12, wherein the processor is configured to temporarily stop transmitting a code sequence of the downlink to reduce overhead. The apparatus of claim 13, wherein the processor is configured to temporarily stop transmitting one or more code sequences of the downlink to reduce overhead. 15. The apparatus of claim 14, wherein the processor is configured to temporarily stop transmitting the code sequence of the downlink to reduce overhead. 8. The method of claim 7, further comprising inferring when to send a request to relay the code sequence to the synchronized terminal based at least in part on the instantaneous, temporally or spatially averaged channel quality indicators of the synchronized terminals in the serving cell. Further comprising an intelligent component. 9. The method of claim 8, further comprising: when transmitting a request to relay the one or more code sequences to the synchronized terminal based at least in part on instantaneous, temporally or spatially averaged channel quality indicators of the synchronized terminals in the serving cell. The apparatus further comprises an inferring AI component. 10. The method of claim 9, further comprising inferring when to send a request to relay the code sequence to the synchronized terminal based at least in part on the instantaneous, temporally or spatially averaged channel quality indicators of the synchronized terminals in the serving cell. Further comprising an intelligent component. 8. The apparatus of claim 7, wherein the apparatus is configured to schedule time and time intervals to operate with frequency reuse. An apparatus operating in a wireless communication environment using orthogonal frequency division multiple access, comprising: A plurality of detection components for simultaneously obtaining a plurality of cell information in a plurality of subcarrier intervals; A processor configured to process the plurality of cell information; And A memory coupled to the processor, the memory storing data; Device. A device operating in a wireless communication environment, Code of primary sync channel symbols, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary detection Means for receiving a sequence; And Means for receiving one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth, Device. 24. The apparatus of claim 23, further comprising means for receiving a code sequence of broadcast channel symbols that carries at least one of a cyclic prefix timing and the wireless system bandwidth. 25. The apparatus of claim 24, further comprising: means for receiving a code sequence of sync channel symbols transmitted at 1.25 MHz; And And means for receiving a code sequence of broadcast channel symbols transmitted at 1.25 MHz or 5 MHz. A machine-readable medium comprising instructions which, when executed by a machine, cause the machine to perform the following steps, the steps of: Code of primary sync channel symbols, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary detection Receiving a sequence; Receiving one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; And Receiving a code sequence of broadcast channel symbols, carrying at least one of a cyclic prefix timing and the wireless system bandwidth. A machine-readable medium comprising instructions which, when executed by a machine, cause the machine to perform the following steps, the steps of: Code of primary sync channel symbols, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary detection Transmitting the sequence at 1.25 MHz; Transmitting one or more code sequences of secondary sync channel symbols at 1.25 MHz, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth, Machine-readable medium.  A method used in a wireless communication system, A primary synchronization channel (P−), carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection, and sub-frame boundary detection; Receiving a code sequence of SCH); Receiving one or more code sequences of a secondary synchronization channel (S-SCH), carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; Receiving a code sequence of a broadcast channel (BCH), carrying at least one of cyclic prefix timing and the wireless system bandwidth; And Processing the P-SCH, the S-SCH and the BCH code sequences to extract the cell information carried by the code sequences; Way. 29. The method of claim 28, further comprising: receiving a code sequence of the primary and secondary synchronization channels at 1.25 MHz; And Receiving the code sequence of the broadcast channel at 1.25 MHz or 5 MHz. 29. The method of claim 28, further comprising: storing the cell information extracted from the first and second synchronization channels and the broadcast channel; And Relaying the cell information. 29. The method of claim 28, further comprising scheduling a time for relaying the cell information. An electronic device configured to carry out the method of claim 28. A method used in a wireless communication system, Code of primary sync channel symbols, carrying at least one of a cyclic prefix period, a portion of a cell identification code, an indicator of broadcast channel bandwidth and facilitating orthogonal frequency division multiplexing symbol boundary detection, slot boundary detection and sub-frame boundary detection Transmitting the sequence; Transmitting one or more code sequences of secondary sync channel symbols, carrying at least one of a radio frame boundary, part or all of a cell identification code, and an indicator of a broadcast channel bandwidth; And Transmitting a code sequence of a broadcast channel, carrying at least one of cyclic prefix timing and the wireless system bandwidth, Way. 34. The method of claim 33, further comprising transmitting a code sequence of symbols for the primary and secondary synchronization channels and a code sequence of symbols for the broadcast channel using frequency reuse. 34. The method of claim 33, wherein the code sequences are Walsh-Hadamard sequences. 34. The method of claim 33, wherein the code sequence is a Gold sequence. 34. The method of claim 33, wherein the code sequences are pseudonoise sequences. 34. The method of claim 33, wherein the code sequences are maximum length sequences (M-sequences). 34. The method of claim 33, wherein the code sequences are generalized chirp like sequences. 34. The method of claim 33, wherein the code sequences are any combination of a Walsh Hadamard sequence, a Gold sequence, a pseudonoise sequence, a maximum length sequence, and a generalized chirped sequence. An electronic device configured to carry out the method of claim 33.

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